A wireless communications system generally comprises of a number of “mobile stations,” where the mobile stations are typically the endpoints of a communications link, and communications infrastructure comprising base stations and controllers, where the communications infrastructure is typically stationary and the intermediaries by which a communications link to a mobile station may be established or maintained. To establish or maintain the communications link to a mobile station, there is an exchange of information specifically concerned with the establishment and control of communications links. In a trunked system, such exchange of information is termed “signaling” and takes place on a control channel of the wireless communications system.
There are many types of control channel architectures that a wireless communications system can use. For example, a wireless communications system may utilize a dedicated control channel, may utilize a dynamic (also known as non-dedicated) control channel that supports both control signaling and traffic on the same channel, or may distribute the control channel functionality among a number of RF channels. For example, a system with a large number of RF frequencies may utilize a dedicated control channel whereas a system with a small number of RF frequencies may utilize a dynamic control channel architecture so that the number of channels in the wireless communications system may be optimized. In another example, a system that supports many traffic channels may allocate multiple slots of a TDMA channel for a control channel functionality whereas a system that supports few traffic channels may allocate a single slot of a TDMA channel for a control channel functionality so that the number of channels in the wireless communications system may be optimized. In another example, a system operating under one set of spectrum regulations may utilize a dedicated control channel whereas a system operating under another set of spectrum regulation may utilize distributed control channel architecture so that the legal restrictions can be met.
Normally, the communications infrastructure comprises of one type of control channel architecture, e.g. a single dedicated control channel, and that control channel architecture does not change. In such a case, the mobile station does not need to be informed of the control channel architecture because the mobile station knows of the control channel architecture a priori as well as other system related parameters for the mobile station to operate with the communications infrastructure. Thus, there is no need to inform the mobile station of the control channel architecture where the control channel architecture does not change.
It would be beneficial to have a communications infrastructure that dynamically changes the control channel architecture based upon performance of the wireless communications system or the operator's need to allocate RF resources between control and traffic. In such a case, the communications infrastructure would need to inform the mobile stations in the wireless communications system of the control channel architecture. Further, it would be beneficial to be able to accommodate disparate wireless communications systems where the control channel architecture may be of one type in one wireless communications system and of another type in another wireless communications system. In such a case, the communications infrastructure would need to inform the mobile stations moving from one system to the other of the different control channel architectures.
Accordingly, there is a need to inform mobile stations of control channel architectures.
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